Reactor vessels, such as those used in polymerization reactions, often operate under either high pressure or vacuum. These reactor vessels are designed to withstand a predetermined pressure. If the designed pressure of the reactor tank is exceeded, then there is a possibility of the reactor vessel exploding. In order to insure against a potential explosion, it is common practice to provide a rupture disc or diaphragm on the reactor vessel. These rupture discs are designed to rupture at a pressure lower than the design rupture pressure of the reactor vessel. Once the disc ruptures, the pressure inside the reactor is relieved thereby preventing further pressure buildup in the reactor vessel. These rupture discs may be unreliable because they may develop small pin-hole leaks which then allow pressure to increase behind the rupture disc. With a back pressure on the reverse side of the disc, a greater pressure is then required in the reactor vessel in order to rupture the disc. Under these circumstances, it is possible that the reactor vessel may explode even though a rupture disc is present in the reactor vessel. The present invention alleviates this problem.
A pressure gauge installed behind the rupture disc to detect a pressure increase caused by a leak is unsatisfactory in the use of reactor vessels due to the vibration caused by the agitator blades in the reactor tank. The gauges under these conditions become unworkable in a short period of time. Reactor vessels are often very large and an operator standing on the floor cannot visually ascertain the pressure shown by the gauge.
The present invention provides means for signaling an operator when a leak has occurred in a rupture disc whether the pressure in the reactor vessel is normal or abnormal.